Dual rcds tripping

[Davem]

Evening gents bit of advice required please I have recently finished a partial rewire (upstairs sockets upstairs lights and smokes). All is fine apart from when I turned under unit lights on in kitchen it tripped both rcds. There is 1 2 gang switch in kitchen 1 for main kitchen light and 1 for under unit I have taken link out from main light switch the under unit light switch and this rectified the problem no tripping but when I put link back in both tripped again and ideas guys cheers by the way pretty new to the game so be nice

 

[Pete999]

You need to carry out an IR test on the suspect circuit, more than likely a NE fault.

 

[spark 68]

More than likely you have one or more N in the wrong N bar if it is tripping both

 

[Zebra Stripe]

Big mistake mate with the "new to the game" and "be nice bit"..tripped both RCDs?? christ why does none of this exciting stuff happen to me?

 

[GMES]

As above sounds like crossed neutrals, time to get the tester out

 

[onions1066]

Did you check for a borrowed neutral before swapping the board?.

 

[Johnuk]

as above mate

 

[GMES]

Did you check for a borrowed neutral before swapping the board?.

I'll have a tenner on that being a no

 

[Zebra Stripe]

Hey little bit of advise, type your post up in word, then go away for 10 mins or so, then come back and read it, edit it then post it.

 

[Davem]

Back there tomorrow guys working Sundays love it so will do as advised I have tested all new installation and all is fine gotta test old bit tomorrow looking forward to it a will get back to you with results cheers guys

 

[onions1066]

It's more important to test the existing installation prior to installing a new board. It will save you being in the situation you are in now.

 

[telectrix]

bet it's a shared neutral between 2 lighting circuits or a N in wrong bar in CU.

 

[Zebra Stripe]

bet it requires a bit of simple logical thinking and some know how and possibly a dash of electrician

 

[Davem]

No borrowed neutral all lighting is segregated to individual circuits Everything works fine other than under unit lights

 

[onions1066]

Where are the under unit lights switched from? I had a similar problem once . They picked the live from the kitchen switch and a neutral from a kitchen socket.

 

[Marvo]

Did you IR test the lighting?

 

[Zebra Stripe]

Can you do a diagram of how youve wired them? if not I'd have to come round and have a look at £30 per hour......sorry but nothing like this ever happenes to me cos Im perfect.

 

[GMES]

This is exactly the reason why pre-testing is so important and should be as important a job as making sure the kettle is boiled before you kill the power. test test and test again

 

[SPARTYKUS]

Let us know what the fault is.

I will be nice, all I ask of you is that you do not take offence to any comments! Take it as tea break banter,

and you will be a winner

 

[telectrix]

No borrowed neutral all lighting is segregated to individual circuits Everything works fine other than under unit lights

it's possible that the L feed to these under cupboard lights comes from another circuit. rather a borrowed L than a borrowed N.